This invention relates to an apparatus for spraying paint, and more particularly to an apparatus for spraying paint under high hydraulic paint pressures wherein the entire apparatus and paint container are portable for access to a work station which may be remotely located from an electrical power source. The apparatus includes an electric motor for operation on conventional house power, and the apparatus is primarily intended for painting areas in and around houses and other buildings. The apparatus includes an electric extension cord for plugging into a normal 110 volt AC outlet.
Portable paint sprayers have been developed in the past for purposes similar to the present invention. They generally include an electric or gasoline powered pump mounted on a wheeled frame assembly for transporting to a work station. Once located at the work station, a paint container is placed nearby and is fluid coupled to the apparatus by means of a suction hose, and an attached spray hose with spray gun is utilized to enable the operator to spray paint at a distance of from 25 to 50 feet from the apparatus. When the apparatus is again moved to a new work station, it is disconnected from the paint container and wheeled to the new location. The paint container is hand-carried to the same location and again fluid coupled to the apparatus so that painting operations may continue.
The high hydraulic paint pressures utilized in an apparatus of this type create a problem of electrostatic voltage build up which must be dealt with. Paint fluid flow through these systems results in a frictional electrostatic charge accumulating on and along the components in contact with the paint. This electrostatic voltage build up if discharged suddenly, will cause a spark which could ignite paint fumes to create a fire or explosion. Prior art apparatus has minimized this problem by utilizing a grounded wire connected between the electric motor assembly and the paint spray gun to drain off any electrostatic potentials that would otherwise develop. Electrostatic potentials developed on or in the paint container itself are a lesser problem, and it has been assumed that these voltages discharge by virtue of the fact that the paint container is generally placed upon the ground. To the extent that electrical continuity is imperfect, there still remains an electrostatic discharge hazard in following this procedure, and it may be recommended by manufacturers of such equipment to provide an auxiliary ground connection between the paint container and the motor assembly.